External threats

The perennial push of exotic plants

onnative plants are everywhere in the national park system and new invaders arrive almost daily. More than 194 parks have recognized the threat they pose to natural resources, and these parks have identified more than 550 project statements in their resource management plans to address this serious problem. In attempting to manage the exotic invaders, the National Park Service spends about $2 million annually. However, the unmet needs detailed in these project statements exceed $20 million each year. Thus, the National Park Service is only able to provide one-tenth of the needed resources to address this threat.

Despite this shortfall, many parks are actively engaged in efforts to manage nonnative plants. Sharp-eyed employees at Big Bend and Redwood National Parks spotted Russian thistle (tumbleweed) and yellowstar thistle in loads of gravel and fill brought into the parks and removed these species before they could become established. Jewel Cave National Monument, South Dakota, worked with surrounding landowners and the U.S. Forest Service to introduce biological control agents for leafy spurge. Use of the agents will likely eliminate the use of herbicides above the cave, reducing possible contamination of cave resources. These lands will also serve as insectaries where the multiplying insects are distributed to surrounding landowners. In similar efforts, Devils Tower National Monument, Wyoming, and Theodore Roosevelt National Park, North Dakota, have distributed hundreds of thousands of leafy spurge biocontrol agents to neighbors. Through education, many parks are also increasing the awareness of the problems caused by invasive plants and are publishing informational brochures, developing Internet pages, or creating calendars featuring exotics. Lake Mead National Recreation Area, Nevada, and Great Smoky Mountains National Park, Tennessee and North Carolina, have developed exotic plant hit teams to assist other parks with management of these species.

An important development in 1996 was the completion of an exotic plants management plan for the National Park Service. Preserving Our Natural Heritage: A Strategic Plan for Managing Invasive Nonnative Plants on National Park Service Lands provides a blueprint for developing park-specific action plans for managing invasive plants. The plan emphasizes partnership activities and goals based on the principles of integrated pest management.

Going beyond the park focus, the National Park Service also worked with Department of the Interior and Department of Agriculture and other groups in 1996 to develop a national strategy for dealing with invasive plants. This strategy, called Pulling Together A National Strategy for Invasive Plant Management, is the first national model for addressing this significant threat to the nation's natural resources. More than 100 federal or state agencies or private groups have endorsed this strategy. However, the two strategies are only just beginning. Much work needs to be done to regain the lands from these invaders and to prevent new invasions from occurring.

Other articles in the "Threats" chapter:

Threats and information

Demographics and resource preservation

Lake trout threaten native Yellowstone cutthroat

Communication breakdown over drilling near Lechuguilla Cave

Historic water rights settlement averts threats at Zion

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This material is from Natural Resource Year in Review--1996, published by the National Park Service, U.S. Department of the Interior, in May 1997 (publication D-1182) http://www2./YearInReview/yir/yr_rvw96/chapter1/exotics.htm
Last Update: 8/20/2002